Final answer:
Polyatomic ions are charged entities composed of multiple atoms, like the nitrate ion (NO3-) which has one nitrogen atom and three oxygen atoms with a -1 charge. Oxoanions such as nitrate and nitrite differ in their oxygen content but share the same charge.
Step-by-step explanation:
Nitrate and Polyatomic Ions
Polyatomic ions are charged species composed of two or more atoms covalently bonded, or of a metal complex that can be considered as acting as a single unit. The characteristic feature of a polyatomic ion is that it carries an overall ionic charge. A common example is the nitrate ion, with the chemical formula NO3−, consisting of one nitrogen atom and three oxygen atoms and carrying an overall charge of -1.
Polyatomic ions, including nitrate, are often found as part of ionic compounds. For instance, when we see calcium nitrate, the formula is Ca(NO3)2.
The term 'oxoanions' is used to describe polyatomic ions containing oxygen, such as nitrate and nitrite. These differ in the number of oxygen atoms present: nitrate has three, while nitrite (NO2) has two, and both carry the same charge of -1. The 'ate' and 'ite' suffixes signify more oxygen and fewer oxygen atoms, respectively.